Trinitron KD-36FS130 sudden issues

[Electronic M]

Originally Posted by YamahaFreak

I do know it's not a weak CRT, as I have a KV-27S25 in the back waiting for a tube swap that exhibits those exact symptoms. (Flashing for a while before finally coming up, and seriously out of whack colors and convergence on the CRT) The 36" one looked perfect before it decided to start wigging out. I have heard of the MCZ chips on the power supplies dying...I suppose that could be the issue, though I hope not, as I'm garbage at soldering those large ICs. I really wish they'd put them in sockets!! I have a 32-inch flat screen Trinitron that needs one of those chips. (Some models have a pair of these ICs)

They are (IIRC 18 pin) DIP chips. Just buy a DIP socket with the correct number of pins and install the socket, then once the socket is soldered pop the chip in. I'm not the best at soldering PCBs either and I did just that (I did use a spring plunger type solder sucker)...I also added a heat sink and in the 2-3 years since the MCZ I changed hasn't failed...the other MCZ (my set uses 2 of them) hasn't failed yet (knock on wood).

I think I also solved what I believe was an intermittent heater cathode short issue last week. What I did was measure heater voltage and current, disconnect the socket heater terminals from the PCB and connected a small 6V relay that draws less current than the 6.3V 450ma heater and used that relay to switch on and off a new floating heater power supply I built from a 120V to 12V stepdown transformer a bridge rectifier and a LM317 regulator circuit (configured to output 6.3V). I also connected the heater to ground through a 1M resistor and .05uF cap to bleed charge down and ground any AC noise. Before this the set would have grayscale disturbance followed by it going red screen (with retrace lines) and triggering an automatic shutdown....in the week since it has only had 1-2 grayscale disturbances that have fixed themselves.